1. Nomenclature Chemical Formulas Reactions

2. Which is an example of a synthesis reaction?
A. HCl + KOH  KCl + H2O
B. Pb(NO3)2 + 2HBr  PbBr2 + 2HNO3
C. C + O2  CO2
D. Mg + H2SO4  MgSO4 + H2

3. The coefficients of the correctly balanced equation for the reaction illustrated are —

4. Which of the following equations is balanced?

5. What would be the product(s) of this reaction?
A. 2Mg3Al2O2
B. Mg3Al2 + 3O2
C. 6Mg + Al3O2
D. 3Mg + Al2O3

6. Elements from which two groups in the periodic table would most likely combine with each other to form an ionic compound?
A. 1 and 2
B. 16 and 17
C. 1 and 17
D. 17 and 18

7. The diagram is a potential energy curve for a reaction
The diagram is a potential energy curve for a reaction. Which number represents the effect of a catalyst on the reaction?
A. 1
B. 2
C. 3
D. 4

8. Which is the correct formula for iron (III) sulfate?
A. Fe3(SO4)2
B. FeSO4
C. Fe2(SO4)3
D. Fe2(SO3)3
Remember the Roman Numeral is the charge of the Iron
*Fe’s oxidation number

9. Which of these represents the empirical formula and the molecular formula, respectively, for a given organic compound?
A. CH and C2H2
B. CH and CH4
C. CH2 and C2H2
D. CH3 and C3H12
Empirical formula is the simplest whole number ratio
Molecular formula is a multiple of the Empirical formula

10. The system that shows a decrease in entropy (disorder) is —
air escaping from a tire
snow melting
salt dissolving in water
water freezing

11. In chemical compounds, covalent bonds form when —
A. the electronegativity difference between two atoms is very large
B. electrons are completely transferred between two metals
C. pairs of electrons are shared between two nonmetal atoms
D. two nonmetal ions are attracted to each other by opposite charges

12. Each beaker shown above contains 2
Each beaker shown above contains 2.2 grams of iron and 1 liter of 3M H2SO4 at STP. Which reaction will go to completion first and why?
A. Beaker A because of increased surface area
B. Beaker B because of increased surface area
C. Beaker A because of a higher concentration level
D. Beaker B because of a higher concentration level

13. A catalyst is a substance used in chemical reactions to —
A. provide a higher activation energy pathway
B. decrease collisions between reactant molecules
C. increase the rate of the reaction
D. change the equilibrium to favor products

14. Which reaction type best describes the reaction above?
A. Combination
B. Decomposition
C. Single replacement
D. Combustion

15. ? AgNO3 + ?AlCl3 → ?AgCl + ?Al(NO3)3
Which of these sets of coefficients will balance this equation?
A. 3, 3, 2, 1
B. 3, 1, 3, 1
C. 1, 6, 1, 9
D. 9, 3, 3, 3

16. The formula for lithium nitride is —
A. LiN
B. Li3N
C. Li3N3
D. NLi3

17. This diagram of a chemical reaction shows that the reaction is —
A. endothermic
B. exothermic
C. reversible
D. at equilibrium

18. Ni(C2H3O2)4 How many atoms are represented in this formula?
B. 8
C. 28
D. 29

19. The correct structural formula for C2H4 is

20. What type of reaction does this illustration represent?
A. Decomposition
B. Synthesis
C. Single-replacement
D. Double-replacement

21. Which of these reactions shows simple chemical decomposition?

22. A compound has 50% sulfur and 50% oxygen. What is its empirical formula?
SO4
S2O4
SO3
SO2

23. A compound has 50% sulfur and 50% oxygen. What is its empirical formula?

24. A compound has 50% sulfur and 50% oxygen. What is its empirical formula?
SO4
S2O4
SO3
SO2

25. The Lewis electron dot system represents electrons in the —
A. outer energy level
B. inner level
C. middle level
D. core level X

26. A(s) + B(s)  D(g) + heat The reaction shown above is —
A. an endothermic reaction
B. an exothermic reaction
C. a decomposition reaction
D. a double-replacement reaction

27. The correct name for MgI2 is —
A. magnesium iodide
B. magnesium iodite
C. magnesium (II) iodide
D. magnesium diiodide

28. If the diagram were the correct representation for the Lewis structure of a molecule, then the X would be representative of the element —
A. oxygen
B. fluorine
C. nitrogen
D. sulfur

29. Chlorine and bromine are in the same family in the periodic table
Chlorine and bromine are in the same family in the periodic table. According to the information in the table, what would be the correct formula for sodium bromate?
A. NaBrO
B. Na2BrO
C. Na3BrO3
D. NaBrO3

30. Which of the groups below has the electron dot structure shown above?
A . Noble gases
B. Halogens
C. Alkali metals
D. Transition elements

31. When naming a transition metal that has more than one oxidation number, the numeric value of the oxidation number is indicated by a —
A. Roman numeral
B. Greek prefix
C. subscript
D. suffix

32. A compound is composed of 85. 64% carbon and 14. 36% hydrogen
A compound is composed of 85.64% carbon and 14.36% hydrogen. The compound has a formula mass of grams. What is the molecular formula?
A. CH2
B. C3H6
C. C2H4
D. C2H18

33. Which of the following is the correct molecular shape of CH4?
A. Bent
B. Linear
C. Pyramidal
D. Tetrahedral

34. According to the table, which of these probably has the strongest bonds?
A. Hydrogen gas
B. Iron crystals
C. Sodium chloride
D. Water

35. The empirical formula for ethyne (C2H2) is —
A. CH
B. C2H2
C. CH2
D. C2H

36. The type of reaction represented by the above equation is —
A. single-replacement
B. double-replacement
C. synthesis
D. decomposition

37. When this equation is correctly balanced, the coefficient of the AlCl3 will be —

38. A catalyst accelerates a chemical reaction because the —
A. catalyst decreases the number of collisions in a reaction
B. activation energy of the reaction is lowered in the presence of a catalyst
C. catalyst decreases the concentration of the reactants
D. temperature of the reaction increases due to the catalyst

39. A compound is composed of 58. 8% C, 9. 8% H, and 31
A compound is composed of 58.8% C, 9.8% H, and 31.4% O, and the molar mass is 102 g/mol. What is the molecular formula for this compound?
A. C2H10O 3
B. C5H5O3
C. C5H10O2
D. CH3O3

40. Which of these completes this reaction?
A. Oxygen
B. Hydrogen
C. Metal oxide
D. Air

41. A balanced chemical equation has equal numbers of atoms of each type on both sides of the equation. This illustrates the principle of —
A. conservation of energy
B. conservation of mass
C. action and reaction
D. natural selection

42. The type of bond found in magnesium chloride is —
A. covalent
B. nonpolar
C. ionic
D. metallic

43. If the temperature of a reaction is increased, the reaction proceeds at a much quicker rate because the —
A. activation energy increases
B. energy of the products increases
C. frequency of collisions between reactants increases
D. energy of the activated complex increases

44. In the above reaction, a cloudiness at completion due to colloidal suspension of sulfur appears. If the reaction is carried out at various temperatures, at which temperature would it proceed at the fastest rate?
A. 20º C B. 30º C C. 40º C D. 50º C

45. The formula H2SO4 is representative of which of the following?
A. A catalyst
B. A base
C. An acid
D. An organic compound

46. A heated liquid placed in a closed container will vaporize until —
A. the boundary between liquid and vapor disappears
B. all the liquid molecules become vapor molecules
C. the number of liquid molecules vaporizing equals the number of vapor molecules condensing
D. the vapor pressure is greater than the atmospheric pressure

47. Which compound contains both ionic and covalent bonds?
A. NH4Cl
B. MgBr2
C. CH4
D. NH3

48. Which of the following containers of water best shows dynamic equilibrium between vapor and liquid?

49. To indicate the number of atoms of each element present in a molecular compound, scientists use —
A. Roman numerals
B. superscripts
C. prefixes
D. subscripts

50. Using the chart, which of these combinations will probably form a precipitate?
A. Ammonium chloride
B. Barium bromide
C. Calcium chromate
D. Copper (II) carbonate

51. The correct name for the compound CCl4 is —
A. carbon tetrachloride
B. carbon chloride
C. monocarbon chloride
D. tetracarbon monochloride

52. Which of these is the general formula for a double-replacement reaction?
A. A +B  AB
B. AB + XY  BA + YX
C. AB + XY  AY + XB
D. A + B + XY  AX + BY

53. The correct formula of an ionic compound containing Al3+ and CO32- is —
A. AlCO3
B. Al(CO3)3
C. Al2(CO3)3
D. Al3(CO3)2

54. Aluminum +Sulfuric Acid  Aluminum Sulfate + Hydrogen Gas
Which of the following is the balanced chemical equation for the reaction shown above?
A. Al + H2SO4  Al2(SO4)3 + H2
B. 2Al + 3H2SO4  Al2(SO4)3 + 3H2
C. 2Al + 3H2SO4  Al2(SO4)3 + H2
D. 2Al + H2SO4  Al2(SO4)3 + H2

55. The figure shows a compound containing hydrogen (H) and an unknown element Z. To which group on the periodic table does element Z belong?
The element Z forms three bonds which means it has 3 valance electrons in addition to the pair show. That gives it 5 valance electrons. Which group has 5 valance electrons.
A. 13
B. 14
C. 15
D. 16

56. Which of the following is the name of the molecule PCl3?
Hint:
A. Phosphorus trichloride
B. Phosphorus chloride
C. Potassium trichloride
D. Potassium chloride

57. The appropriate model for a decomposition reaction is —
Synthesis
Single
Displacement
Double
Displacement

58. The formula for dinitrogen tetroxide is —
A. N2O4
B. N3O3
C. N2O2
D. NO
dinitrogen tetroxide 2 4

59. What is the correct Lewis dot structure for arsenic?
Arsenic (As) is in group 15!
Which means 5 valance electrons
Or 5 dots!

60. The empirical formula for a substance is CH2
The empirical formula for a substance is CH2. If the molecular mass of the substance is 56, the molecular formula is
A. C2H4
B. C3H6
C. C4H8 _
D. C5H10
Molar Mass
CH2 = 1(12) + 2(12) = 14
56/14 = 4
4(CH2) =

61. H2O(l)  H2O(g) Water molecules in a sealed jar are in a state of dynamic equilibrium because water vapor molecules —
Think
A. are condensing at the same rate that others are evaporating
B. cease to form when the air in the jar becomes saturated
C. are evaporating faster than they are condensing
D. form only at high temperatures

62. The diagram shows the structural formula of benzene
The diagram shows the structural formula of benzene. The empirical and the molecular formulas of benzene are, respectively —
A. CH, C2H2
B. CH, C3H3
C. C3H3, C6H6
D. CH, C6H6
6 Carbon atoms and 6 Hydrogen atoms
Divide by 6 gives you ……….

63. Al + HCl  AlCl3 + H2
When the above equation is balanced, the coefficient of the hydrochloric acid will be
A. 2
B. 3
C. 4
D. 6

64. Which graph represents the reaction shown above?
2NO(g) + O2(g)  2NO2(g) ΔH = - 27 kcal
Which graph represents the reaction shown above?
ΔH = - 27 kcal Means the reaction was exothermic releasing energy
Therefore the products have less energy then the reactants

65. Which graph represents the reaction shown above?
2NO(g) + O2(g)  2NO2(g) ΔH = - 27 kcal
Which graph represents the reaction shown above?
Which Graph shows less energy in products than reactants? ? ? ? ? ? ? ?

66. Which of the following occurs when a reaction in a solution is at equilibrium and more product is added to the solution?
A. Equilibrium shifts to produce more product
B. Equilibrium shifts to produce more reactant
C. No change will occur
D. The reaction will stop

67. What shape does the molecule BF3 have?
Boron (B) is in group 13 therefore B has three valance electrons.
Fluorine (F) is a Halogen and therefore has 7 valance electrons
F and B Bond by 3 bonds
A. Bent
B. Linear
C. Tetrahedral
D. Trigonal planar F B F F

68. When the above equation is balanced, the coefficients in order are —
CaSO4 + Al(OH)3  Ca(OH)2 + Al2(SO4)3
When the above equation is balanced, the coefficients in order are —
A. 1, 1, 1, 1
B. 2, 1, 1, 2
C. 3, 1, 3, 2
D. 3, 2, 3, 1

69. The correct name for P2O5 is —
A. phosphorus (V) pentoxide
B. phosphorus oxide
C. phosphorus (II) oxide
D. diphosphorus pentoxide

70. Which set of coefficients will balance this equation?
D. 3, 6, 3, 2

71. Using the table, what is the correct formula for ammonium phosphate?
A. NH4PO4
B. (NH4)2(PO4)3
C. (NH4)3PO4
D. NH4(PO4)3

72. Which half-reaction represents reduction?
A. Cu0 → Cu+2 + 2e-
B. Fe+2 → Fe+3 + 1e-
C. Ag+1 + 1e- → Ag0
D. Al0 → Al+3 + 3e-

73. Which of the following best represents the reaction between hydrochloric acid and sodium hydroxide?
A. 2HCl + 2NaOH → Na(OH)2 + H2Cl2
B. HCl2 + 2Na(OH)2 → 2H2O +2NaCl + OH
C. HCl + NaOH → H2O + NaCl
D. 2HCl + Na(OH)2 → 2H2 + NaCl + O2

74. The type of formula that shows the arrangements of atoms and bonds is called —
A. empirical
B. chemical
C. molecular
D. structural

75. What is the molecular formula of a substance that has an empirical formula of C2H5 and a molecular mass of 58 g/mole?
A. C2H5
B. C5H2
C. C4H10
D. C6H15
Molar Mass C2H5 = 2(12) + 5(1) = 29g/mole
58/29 = 2
2(C2H5) = C4H10

76. Which type of reaction is represented here?
Switch
Na2CO3 + Ca(OH)2  2NaOH + CaCO3
Which type of reaction is represented here?
A. Single replacement
B. Double replacement
C. Synthesis
D. Decomposition

77. The empirical formula for C6H12 is —
A. C3H6
B. C2H4
C. CH3
D. CH2

78. Which completes the chemical equation above?
2O3 (g)  3 ______ (g)
Which completes the chemical equation above?
A. O2
B. O3
C. ClO
D. ClO2
Total of 6 O